Rotary drilled hole enlarger



P 4, 1951 J. LIVINGSTONE 2,566,671

ROTARY DRILLED HOLE ENLARGER Filed Aug. 21, 1948 m lunl l l-llllH INVENTOR.

.J A M ES L.l v l NGSTONE Patented Sept. 4, 1951 UNITED STATES PATENT OFFICE ROTARY DRILLED HOLE ENLARGER James Livingstone, San Francisco, CalifQassignor to Pearl Edith Livingstone, San Francisco, Calif.

Application August 21, 1948, Serial No. 45,516

3 Claims.

This invention relates to rotary drilled hole enlarger.

In the present practice it is rather tedious and difficult to enlarge the bottom or inner end of a drilled hole in rock drilling and blasting, for the purpose of forming a pocket into which the explosive charge could be packed for greater effectiveness.

The primary object of my invention is to provide a device which can be readily inserted in a drilled hole and then released for laterally expanding operation and rotated so as to enlarge the bottom of the hole into a pocket; and which device can be easily contracted for withdrawal from the hole after the pocket is completed.

Another object of the invention is to provide a pocket forming tool for the bottoms of drilled holes which tool can be easily attached to the usual usual rock drills for guiding and operation.

I'amaware that some changes may be made in the general arrangements and combinations of the several devices and parts, as well as in the details of theconstruc'tion thereof without departing from the scope of the present invention as set forth in the following specification, and as defined in the following claims; hence I do not limit my invention to the exact arrangements and combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

With the foregoing and other objects in View, which will be made manifest in the following detailed description, reference is had to accompanying drawings for the illustrative embodiment of the invention, wherein:

' Fig. 1 is a side view of the device shown in the drilled hole after the pocket is formed, the broken lines indicate the connection to an electric motor mounted on the usual rock drills.

Fig. 2 is a section view of the tool showing'it in contracted position and also showing the means for contracting the tool for the purpose of withdrawal.

Fig. 3 is a sectional view of the tool the sec tion being taken, on the lines 3-3 of Fig. 2

Fig. 4 is a sectional view of the tool the section being taken on the lines 4-4 of Fig. 2, and Fig. 5 is a fragmental sectional view of the tripping device in the ends of the leafspring of the tool.

In the illustrative embodiment of my invention I make use of a tube I, one end of which is externally threaded at 2. The other end of the tube I has. parallel diametrically opposite slots 3 extended from the extreme end of the tube I longitudinally of the tube and parallel with the axis thereof. A retaining pin 4 is extended through the tube substantially at right angles to the diameter on which the slots 3 are located and at right angles to said slot 3. The pin 4 is beyond the bottom or inner ends of the slots 3. A substantially V-shaped leaf spring. 5 has its apex 1 engaged with the underside of the pin 4 and has its legs extended outwardly through the slotted end of the tube I so that they extend substantially beyond the said end of said tube I. On the outer end of each leg of the leaf spring 6 is secured a suitable reamer 8 by any suitable securing element, such as screws or rivets 9. Each reamer element 8 is generally semi-cylindrical with the outer end thereof tapering inwardly. The. outer surface of each reamer section 8 is roughened or provided withcutting teeth I! to act against the sides of the holes for enlarging the same when rotated.

A, tripping device isprovided. to hold the semicylindrical reamer sections 8 in contracted position for insertion into a drilled hole I2, so that the reamer does not expand for forming a pocket until after it reached near the bottom I3 of said drilled hole I2. In the present form this is ac companied by bending the outer end of the leaf spring 6 inwardly into retaining hooks I4 and engaging said retaining hooks by a transverse clamp I 6 well within the space between the reamer sections 8. A tripping finger I'I extends from the clamp I6 outwardly of the tool and slightly beyond the tips of the reamer section 8, so that it will abut the bottom I3 of the drilled hole I2. The pressure exerted in inserting the tool into the hole I2 will cause the finger IT to be pushed in by the hole bottom I3 thereby pushing the clamp I6 out of the hooks I4 of the leaf springs 6 and allowing the latter to expand. The slots 3 on the tube I are such as to allow expansion of the leaf spring 6 outwardly beyond the outer periphery of the tube I and of the hole IZ.

The reamer sections 8 are contracted for the initial operation of insertion and withdrawal by a tubular rod I8 slidable inside of the tube I. The inner end of the rod I8 is forked, the prongs I5 of the fork are so spaced that they engage is inserted into the tube I and compress the same. The leaf spring 6 is necessarily of considerable strength and the compression is accomplished by any suitable device whereby leverage can be exerted upon the rod I8. In the present illustrathe legs of the leaf spring 6 as the rod I8.

force to compress the leaf spring 5.

tion a cap '20 is threaded on the threaded end 2 of the tube I. In the center of the cap 20 is axially threaded a screw 2|, the inner end 22 of which is rotatable in a plug 23 which latter is fixed by threading, or otherwise, into the outer end 24 of the rod it. Thus after the rod I3 is inserted into the tube I so far as it can be pushed manually, the cap 20 is screwed upon the threaded end 2 of the tube I and thereafter applying a leverage to the head 25 of the screw 2| the latter can be turned so that it moves inwardly of the tube I pushing the rod I8 inwardly by suflicient After the leaf spring 6 is so compressed the tripping clamp I6 is inserted under the hooks I 4 and the leaf spring is released by removing the forked rod I8 and the clamp I5 holds the spring against expansion. The width of the clamp I6 is such that it does not allow the expansion of the leaf spring 6 beyond the point where the outer peripheries of the reamer sections 8 are generally Within the diameter of the tube I andof the hole I2. I

The unit with the contracted reamer sections 8 is then inserted in the hole l2 either manually or by any suitable extension rod, and when the tool reaches the bottom I 3 of the hole I2 the clamp I5 is tripped in the manner heretofore described and the jaws or reamer sections 8 are allowed to expand from the reaming or pocket forming operation. In some instances it may be necessary to rotate the tool in a tight hole I2 for insertion.

.In such instances the tool is rotated but the reamer sections 8 are not permitted to form a pocket until the tool is thus reamed into the hole I2 to the bottom I3 where the tripping operation is performed as. heretofore described. In this manner it is assured that the pocket forming *operation occurs only at the bottom of the hole [2.

In the present illustration an extension rod 21 is secured by a suitable coupling 23 to the threaded end 2 of the tube I.. Both the tube I or the extension rod 27 may be of the suitable length to extend into drilled hole I2 of any depth. Rotation is imparted to the tool in any suitable manner, but it is preferable that the usual rock drill mechanism of any suitable type, not herein shown, may be employed. The extension rod 21 is preferably journalled at its rear end 29 inthe socket 3i formed in the end of the usual rock drill device wherein the rod for the usual drill bit is otherwise held. On the extension rod 27 is a transmission pulley 32, which by suitable belting 33, indicated in broken lines, is connected to the pulley 38 of an electric motor 36 which latter is mounted on a bracket 37 on one side of the usual rock drill casing 38. The electric motor 35 is connected to a source of electricity in any suitable manner and is controlled by a suitable switch, not shown. It is to be noted that the extension rod 2! and the coupling 28 are both provided with a central water passage 39 which is aligned with the usual water passage of such rock drill device so as to furnish the water for the reaming operation. Ihe operator holds the rock drill for the insertion and operation of the tool similarly to the holding of the same for any drilling operation, then it operates the motor 36 and as the tool rotates it will expand and form a pocket 4| as indicated in Fig. 1.

After the pocket is formed the coupling 28 is disconnected from the threaded end 2 of the tube I and the contracting or compressing rod I8 is inserted in the manner heretofore described to compress the leaf spring 6 thereby allowing the withdrawal of the tool from th pocket and from the hole I2. In the event of a hole deeper than the length of the lowest tube, the compressing rod is of a length, whether single or sectional, to project above the ground level, and the threaded capping is performed on the pipe section at said level.

I claim:

1. In a pocket forming device for the bottom of a drilled hole, a tubular element insertable in the drflled hole, one end of said tubular element having diametrically opposite axial slots at an end thereof, an anchor element in said tubular element adjacent saidslots, a bow spring anchored on said anchor'element and extended beyond the slotted ends of said tubular element and being expansible through said slots beyond the outer periphery of said tubular element, reaming jaws on the outer ends of said bow spring to be urged apart by said spring, a catch device to hold said spring and said jaws in contracted position said jaws being complemental substantially half cylindrical within the circumferential dimensions of said tubular element and of the hole in said contracted position, cutting teeth on the outer peripheries of said jaws, and a tripping member on said catch device abuttable against the bottom of the hole for releasing said catch device and allowing the expansion of said spring and said jaws against the sides of the hole at said bottom.

2. In a pocket forming device for the bottom of a drilled hole, a tubular element insertable in the drilled hole, one end of said tubular element having diametrically opposite axial slots at an end thereof, an anchor element in said tubular element at about said slots, a bow spring anchored on said anchor element and extended beyond the slotted ends of said tubular element and being expansible through said slots beyond the outer periphery of said tubular element, reaming jaws on the outer ends of said bow spring to be urged apart by said spring, a catch device to hold said springand said jaws in contracted position said jaws being complemental substantially half cylindrical within the circumferential dimensions of said tubular element and of the hole in said contracted position, cutting teeth on the outer peripheries of said jaws, and a tripping member on said catch device abuttable against the bottom of the hole for releasing said catch device and allowing the expansion of said spring and said jaws against the sides of the hole at said bottom, a contracting device insertable through the other end of said tubular element for engaging said spring and contracting the same to move the jaws together.

3. In a pocket forming device for the bottom of a drilled hole, a tubular element insertable in the drilled hole, one end of said tubular ele-' ment having diametrically opposite axial slots at an end thereof, an anchor element in said tubular element at about said slots, a bow spring anchored on said anchor element and extended beyond the slotted ends of said tubular element and being expansible through said slots beyond the outer periphery of said tubular element, reaming jaws on the outer ends of said bow spring to be urged apart by said spring, said reaming jaws being substantially semicylindrical and when contracted complemental to a cylinder of substantially the same diameter as the outer diameter of the tubular element, cutting teeth on the outer peripheries of said jaws, a catch device to hold said spring, and said jaws incontracted position within the circumferential di- A A il mensions of said tubular element and of the hole, and a tripping member on said catch device abuttable against the bottom of the hole for releasing said catch device and allowing the expansion of said spring and said jaws against the sides of the hole at said bottom, the other end of said tubular element being adapted for connection to a rotating device for rotating said tubular element and said jaws in said hole, said anchor device being adapted to transmit rotation from said tubular element to said spring and to said jaws.

JAMES LIVINGSTONE.

REFERENCES CITED The following references are of record in the file of this patent:

Number 6 UNITED STATES PATENTS Name Date Salisbury June 30, 1868 Wegner Dec. 15, 1891 Dunn June 2, 1903 Dunham May 20, 1919 Blodgett Apr. 26, 1921 Lewis Nov. 18, 1924 Cooper Nov. 3, 1925 Korts Nov. 30, 1926 Cady June 10, 1941 Kammerer Apr. 12, 1949 FOREIGN PATENTS Country Date 15 Number Great Britain of 1885 

